The Morphology and Clinical Applications Core is a critical component of our Center activities. We are concerned with determining the relevance of our data to human disease, and are particularly interested in the significance of the biologic phenomena studied when viewed against the background of what is known of the natural history of human disease. The opportunity to use a human tissue bank to make crosscorrelations between projects is also particularly important. For example, one would like to correlate the upregulated expression of specific mediator molecules such as osteopontin with evidence of endothelial activation or smooth muscle phenotypic changes within abnormal renal blood vessels or to correlate increased expression of SPARC with resolution of proliferative glomerular lesions. The identification of the various mediator molecules in human development may allow us to identify mechanisms which normally control the expression of such molecules. The Core is therefore intended to provide tissue, technical and intellectual support for the projects, but in turn is designed to extend and amplify the work of the individual projects in order to better understand human renal disease as mandated by the Center grant program.